This invention relates to a demolition agent for brittle materials such as concrete, rocks and bricks etc.
Hitherto, many demolition agents such as explosives, expansion gases and expansion materials have been proposed for brittle materials such as concrete, rocks and bricks etc. Among those, the explosives are a preferable demolition agent because of its strong breakage effect per unit time, but it has disadvantages that it may cause pollution such as noise, flyrock, vibration, dust and the like at an explosion time and that there may be accompanied with a danger during its operation. In order to eliminate such disadvantages, it has been proposed a method wherein a slurry of expansion material is filled into a hole drilled in a brittle material to demolish it by means of the expansive stress of the slurry. By using this method, advantages are obtained such that there is occurred no noise except a noise for drilling, no vibration and less danger. It is considered that quick lime can be used as a demolition agent because of its great expansive stress. It has, however, such a disadvantage that since it has a very high hydration speed and may expand by hydration immediately after being mixed with water, its fluidity is reduced rapidly to become difficult for pouring into the hole. Even though it can be poured, its expansive stress may escape to the direction of a hole opening so that its pressure against the side wall of the hole may become very low. It therefore cannot be used as a demolition agent. In order to overcome this disadvantage, a method may be considered in which a slurry of quick lime is poured into a hole and at the same time a binding cap is fixed on the opening of the hole to restrict its expansive stress, but it is not a preferable method because of its troublesome operation. Another method can also be considered in which silicofluoride and the like added to quick lime to restrict the hydration speed of quick lime. However, it can not be expected to obtain a high expansive stress, since quick lime has no self hydraulic property so that the expansive stress of quick lime may escape to the direction of the opening of the hole. Further, since reactivity of quick lime may be different depending on its burning degree during its preparation, it is very difficult to control its hydration speed.
An object of this invention is to offer a hydraulic demolition agent which hydrate at a relatively low speed and provide large expansive coefficient and expansive stress.
Another object of this invention is to offer a hydraulic demolition agent which can be used at the place of atmospheric temperature higher than 5.degree. C.
Other important objects and advantages features of this invention will be apparent from the following description and the drawings attached.
These objects can be attained in accordance with the present invention.